+ // Rationale: a lot of common operations (including but not
+ // limited to moving, resizing and appending items to a listbox)
+ // unmamange the widget, do their work, then manage it again.
+ // This means that, for example adding an item to a listbox will show it,
+ // or that most controls are shown every time they are moved or resized!
+ XtSetMappedWhenManaged( w, domap );
+